Time trends, frequency, characteristics and prognosis of short-duration transient global amnesia.

BACKGROUND AND PURPOSE: Transient global amnesia (TGA) is characterized by a sudden onset of anterograde amnesia lasting up to 24 h. One major differential for TGA is transient epileptic amnesia, which typically lasts < 1 h. However, TGA can also be short in duration and little is known about the time trends, characteristics and prognosis of TGA cases lasting < 1 h. METHODS: We compared the clinical features of TGA ascertained in two independent cohort studies in Oxfordshire, UK [Oxford cohort 1977-1987 versus Oxford Vascular Study (OXVASC) 2002-2018] to determine the time trends of clinical features of TGA. Results were validated in another independent contemporary TGA cohort in Italy [Northern Umbria TGA registry (NU) 2002-2018]. We compared the risk factors, clinical features and long-term prognosis (major cardiovascular events, recurrent TGA and seizure/epilepsy) of patients presenting with episodes lasting < 1 h versus those lasting ≥ 1 h. RESULTS: Overall, 639 patients with TGA were included (114 Oxford cohort, 100 OXVASC, 425 NU). Compared with the original Oxford cohort, there were more cases with TGA lasting < 1 h in OXVASC [32 (32.0%) vs. 9 (8.8%)] and NU (11.8% vs. 8.8% in Oxford cohort). In both OXVASC and NU, patient age, vascular risk factors and clinical features were largely similar between those with TGA lasting < 1 h versus those lasting ≥ 1 h. Moreover, there was no difference in the long-term risk of seizure/epilepsy or major cardiovascular events between TGA lasting < 1 h versus TGA lasting ≥ 1 h. CONCLUSIONS: Short-duration TGA episodes (<1 h) were not uncommon and were more frequent than in earlier studies. The clinical features and long-term prognosis of short-duration TGA did not differ from more typical episodes lasting ≥ 1 h.

Aggressive behavior in cattle is associated with a polymorphism in the MAOA gene promoter.

Molecular mechanisms underlying aggressive behavior are primitive and similar among the subphylum Vertebrata. In humans, a primary goal in the study of aggression is to determine the neurobehavioral molecular factors triggering violence. Although several species have been used to study agonistic responses, researchers are limited by the difficulty of artificially inducing aggression in animals not selected for it. Conversely, the Lidia cattle breed has been selected since the eighteenth century to display agonistic responses based on traits such as aggressiveness, ferocity and mobility, all of them showing significant heritability values. This intensive selection may have driven shifts in specific allele frequencies. In a previous analysis across the autosomes, we revealed long-term selection regions including genes involved in behavioral development. In the present study, we focus on mapping recent signatures of selection associated with aggressiveness at chromosome X, by comparing Lidia cattle samples with two non-specialized Spanish breeds showing tamed behavior. The most significant markers peaked around the monoamine oxidase A (MAOA) gene, and thus the associations of three functionally important regions located near the promoter of this gene were further investigated. A polymorphism consisting of a variable number of tandem repeats of the nucleotide 'C' (BTX:105,462,494) and displaying lower number of repetitions in the Lidia breed when compared with the tamed breeds was detected. In silico analyses predicted that the g.105,462,494delsinsC variant may code for the Sp1 binding motif, one of the major transcription factors controlling the core promoter and expression of the MAOA gene in humans.

Substantia nigra hyperechogenicity in essential tremor and Parkinson's disease: a longitudinal study.

BACKGROUND AND PURPOSE: Essential tremor (ET) and Parkinson's disease (PD) sometimes overlap in their clinical expression with ET preceding PD onset, often leading to misdiagnosis. Transcranial sonography (TCS) has been shown to be a valid and non-invasive diagnostic tool to identify early idiopathic PD and to differentiate it from ET. The purpose of this study was to investigate the relevance of substantia nigra hyperechogenicity in patients with ET. METHODS: A total of 138 patients (79 with PD, 59 with ET) and 50 matched controls underwent TCS examination at baseline. All patients were followed in a 3-year longitudinal assessment. RESULTS: A total of 10 subjects were excluded from the analysis due to the bilateral absence of a temporal acoustic window. During the follow-up period, 11 of the patients with ET developed new-onset parkinsonian features, without fulfilling criteria for PD diagnosis (ET+). Nine patients developed clinical features meeting diagnostic criteria for probable PD (ET-PD). Patients with ET- did not develop parkinsonian features. For each group, the maximum size of the substantia nigra hyperechogenicity was as follows: 5.62 ± 5.40 mm2 in the control group, 19.02 ± 14.27 mm2 in patients with PD, 9.15 ± 11.26 mm2 in patients with ET-, 20.05 ± 13.78 mm2 in patients with ET+ and 20.13 ± 13.51 mm2 in patients with ET-PD. ET-PD maximum values were significantly different from controls. Maximum values in patients with ET+ were different from both controls and patients with ET-. CONCLUSION: Substantia nigra hyperechogenicity in ET seems to represent a risk marker for developing early parkinsonian symptoms or signs in the 3 years following TCS assessment.

Early management of patients with medication-overuse headache: results from a multicentre clinical study.

BACKGROUND AND PURPOSE: Educational intervention has proved to be effective in reducing drug abuse in uncomplicated medication-overuse headache (MOH). This ancillary of the SAMOHA multicentre study aimed to assess any differences in phenotypic characteristics, type and amount of drugs overused, and comorbidities between patients with MOH who responded to simple advice and those who did not. METHODS: Demographic and clinical headache data of the last 3 months before enrollment of patients were collected and patients were then asked to fill out a daily headache diary for 4 weeks. Patients were then divided into two subgroups, i.e. those with confirmed MOH continued in the study [randomized (R) group], whereas those who did not still show any features of MOH dropped out of the study. RESULTS: A total of 88 (67.7%) patients still met the inclusion criteria after the baseline 4 weeks (R group). Conversely, 42 (32.3%) patients dropped out of the study. A detailed analysis of those who dropped out revealed that only 34 were not randomized at visit 2 because they no longer satisfied the inclusion criteria for MOH [screening failures (SF) group]. The SF group was significantly younger and had fewer years of migraine history than the R group. Moreover, the SF group had a significantly shorter history of chronicity compared with the R group. CONCLUSIONS: Our findings suggest that in MOH trials, after an educational session, an observational period is needed in order to confirm the diagnosis of MOH and to avoid overestimation of the effect of other treatments used to manage MOH. Future research should focus mainly on those patients with MOH who do not respond to simple advice and with unsuccessful withdrawal.

Subclinical vestibular dysfunction in migraineurs without vertigo: A Clinical study.

OBJECTIVES: This observational study aimed to investigate the presence of potential vestibular system subclinical dysfunction among migraineurs without a history of vertigo and dizziness compared with healthy controls. METHODS: Patients diagnosed with episodic migraine with and without aura were enrolled. All patients and healthy controls underwent vestibular examination using the following conventional tests: sitting position, Pagnini-McClure's, Dix-Hallpike's, head hanging, video head impulse, subjective visual vertical, Romberg, Fukuda, and caloric vestibular stimulation by Fitzgerald-Hallpike's tests. Nystagmus and angular velocity of the slow phase during culmination phase was analyzed by video-nystagmography. RESULTS: Overall, 33 patients (76% female, 7 with aura and 26 without aura; mean age (mean ± SD): 29.1 ± 4.3 years) and 22 controls (33% female, mean age: 30.8 ± 9.4 years) were enrolled. There were no statistically significant differences in demographic features between patients and controls. Caloric vestibular stimulation test results were found to differ among patients and controls. In particular, right and left angular velocity (AV) were highly correlated one another (r = 0.88, P < .001). Right AV (53.0 ± 6.7 vs 44.0 ± 9.6) and left AV (54.3 ± 5.3 vs 43.3 ± 9.0) were statistically higher in migraineurs as compared to controls (P < .001). Also right V-HIT (1.1 ± 0.1 vs 0.8 ± 0.4) and left V-HIT (1.1 ± 0.1 vs 0.7 ± 0.2) were statistically higher in migraineurs compared to controls (P < .001). CONCLUSION: Our findings suggest a subclinical alteration of vestibular pathway in migraineurs who have never complained vertigo or postural imbalance. This finding supports the hypothesis of a vestibular-cerebellar dysfunction in migraineurs, particularly among those with aura.

Detection of selection signatures for agonistic behaviour in cattle.

The identification of genomic regions including signatures of selection produced by domestication and its subsequent artificial selection processes allows the understanding of the evolution of bovine breeds. Although several studies describe the genomic variability among meat or milk production cattle breeds, there are limited studies orientated towards bovine behavioural features. This study is focused on mapping genomic signatures of selection which may provide insights of differentiation between neutral and selected polymorphisms. Their effects are studied in the Lidia cattle traditionally selected for agonistic behaviour compared with Spanish breeds showing tamed behaviour. Two different approaches, BayeScan and SelEstim, were applied using genotypic 50K SNP BeadChip data. Both procedures detected two genomic regions bearing genes previously related to behavioural traits. The frequencies of the selected allele in these two regions in Lidia breed were opposite to those found in the tamed breeds. In these genomic regions, several putative genes associated with enriched metabolic pathways related to the behavioural development were identified, as neurochondrin gene (NCDN) or glutamate ionotropic receptor kainate type subunit 3 (GRIK3) both located at BTA3 or leucine-rich repeat and Ig domain containing 2 (LINGO2) and phospholipase A2-activating protein (PLAA) at BTA8.

Neuropsychiatric adverse events of antiepileptic drugs in brain tumour-related epilepsy: an Italian multicentre prospective observational study.

BACKGROUND AND PURPOSE: We assessed the prevalence and magnitude of neuropsychiatric adverse events (NPAEs) associated with antiepileptic drugs (AEDs) among patients with brain tumour-related epilepsy (BTRE). METHODS: This observational, prospective, multicentre study enrolled 259 patients with BTRE after neurosurgery. All patients received AED monotherapy. Efficacy was assessed through clinical diaries, whereas NPAEs were collected using the Neuropsychiatric Inventory Test-12 questionnaire at baseline and after 5 months. RESULTS: Tumour localization in the frontal lobe was associated with a higher prevalence of NPAEs (odds ratio, 7.73; P < 0.001). Independent of tumour localization, levetiracetam (LVT) treatment was associated with higher prevalence and magnitude of NPAEs (odds ratio, 7.94; P < 0.01) compared with other AEDs. Patients with oligodendroglioma reported more NPAEs than patients with other tumour types. NPAEs were not influenced by chemotherapy, radiotherapy or steroid treatment. Evaluating non-neurobehavioural adverse events of AEDs, no significant differences were found among AEDs, although patients treated with old AEDs had a higher prevalence of adverse events than those treated with new AEDs. CONCLUSIONS: Both tumour localization in the frontal lobe and LVT treatment are associated with a higher risk of NPAEs in patients with BTRE. LVT is regarded as a first-line option in patients with BTRE because of easy titration and few significant drug-to-drug interactions. Thus, as NPAEs lead to poor compliance and a high dropout rate, clinicians need to accurately monitor NPAEs after AED prescription, especially in patients with frontal lobe tumours receiving LVT.

Genomic diversity and population structure of Mexican and Spanish bovine Lidia breed.

The Lidia bovine breed is distinguished for its low genetic exchangeability given its selection on aggressive behavior, its management uniqueness and its subdivided structure. In this study, we present a comprehensive genome-wide analysis of genetic diversity, population structure and admixture of 468 animals from Mexican and Spanish Lidia breed populations and 64 samples belonging to 10 Spanish native and American-creole breeds using 37 148 single nucleotide polymorphisms. We found similar average inbreeding values in the Lidia breed, with different distributions within groups; variability of inbreeding values among Spanish lineages was significant and no differences were found among the Mexican sub-populations. Together, the high FIS of the lineages and the behavior of the runs of homozygosity are consequences of the lineage's small effective population sizes, contributing to their inbreeding increase. Population admixture analysis discarded any influence on the genetic structure of the Lidia populations from the Spanish native and American-creole breeds. In addition, both Lidia populations depicted different genetic origins, with the exception of some Mexican individuals whose origins traced back to recent Spanish importations.

A genome-wide association analysis for carcass traits in a commercial Duroc pig population.

We performed a genome-wide association study to map the genetic determinants of carcass traits in 350 Duroc pigs typed with the Porcine SNP60 BeadChip. Association analyses were carried out using the gemma software. The proportion of phenotypic variance explained by the SNPs ranged between negligible to moderate (hSNP2= 0.01-0.30) depending on the trait under consideration. At the genome-wide level, we detected one significant association between backfat thickness between the 3rd and 4th ribs and six SNPs mapping to SSC12 (37-40 Mb). We also identified several chromosome-wide significant associations for ham weight (SSC11: 51-53 Mb, three SNPs; 67-68 Mb, two SNPs), carcass weight (SSC11: 66-68 Mb, two SNPs), backfat thickness between the 3rd and 4th ribs (SSC12: 21 Mb, one SNP; 33-40 Mb, 17 SNPs; 51-58 Mb, two SNPs), backfat thickness in the last rib (SSC12: 37 Mb, one SNP; 40-41 Mb, nine SNPs) and lean meat content (SSC13: 34 Mb, three SNPs and SSC16: 45.1 Mb, one SNP; 62-63 Mb, 10 SNPs; 71-75 Mb, nine SNPs). The ham weight trait-associated region on SSC11 contains two genes (UCHL3 and LMO7) related to muscle development. In addition, the ACACA gene, which encodes an enzyme for the catalysis of fatty acid synthesis, maps to the SSC12 (37-41 Mb) region harbouring trait-associated regions for backfat thickness traits. Sequencing of these candidate genes may help to uncover the causal mutations responsible for the associations found in the present study.

Genetic diversity of the Mexican Lidia bovine breed and its divergence from the Spanish population.

Lidia bovine breed exists since the XIV century in the Iberian Peninsula. These animals were initially produced for meat but some, showing an aggressive behaviour which difficulted their management, were used to participate in popular traditional and social events. A specialization of the breed giving rise to the original Lidia population is documented in Spain since mid-XVIII century. Following the same tradition than in the Spanish population, Mexico used aggressive animals at the beginning of the XX century until two families of breeders started importing Lidia breed bovines from Spain with the aim of specializing their production. Each family (Llaguno and González) followed different breeding managements, and currently, most of the Lidia Mexican population derives from the Llaguno line. Although genetic structure and diversity of the Spanish population have been studied (using autosomal microsatellite markers, Y chromosome DNA markers and mitochondrial DNA sequences), the Mexican population is not analysed. The aim of the study was to assess both the genetic structure and diversity of the Mexican Lidia breed and its relationship with the original Spanish population using the same molecular tools. A total of 306 animals belonging to 20 breeders issued from both existing Mexican families were genotyped, and the genetic information was compared to the previously existing Spanish information. Slightly higher levels of genetic diversity in Mexican population were found when comparing to the Spanish population, and the variability among populations accounted for differences within them showing mean values of 0.18 and 0.12, respectively. Animals from the Mexican breeders, belonging to each of the two families, clustered together, and there was little evidence of admixture with the Spanish population. The analysis of Y chromosome diversity showed a high frequency of the H6 haplotype in the Mexican population, whereas this haplotype is rare in the Spanish, which is only found in the Miura (100%) and Casta Navarra (38%) lineages. Mitochondrial DNA revealed similar haplotypic pattern in both Spanish and Mexican populations, which is in accordance with most of the Mediterranean bovine breeds. In conclusion, as the Mexican Lidia population had initially a small number of founders and its current population has been reared isolated from their Spanish ancestors since a long time, these bottleneck effects and a combination of mixed cattle origin are the factors that might erase any trace of the Spanish origin of this population.

Reliability and validity of the Italian versions of the Children's Fear Survey Schedule - Dental Subscale and the Modified Child Dental Anxiety Scale.

AIM: Children's dental fear and anxiety (DFA) causes significant problems in clinical practice. The 15-item Children's Fear Survey Schedule - Dental Subscale (CFSS-DS) and the 8-item Modified Child Dental Anxiety Scale (MCDAS) are the most widely used measures of dental fear in children. The aim of this study is to examine the reliability and validity of the Italian versions of the CFSS-DS and MCDAS, also in comparison with a simple visual analogue scale (VAS). MATERIALS AND METHODS: The CFSS-DS and MCDAS were translated into Italian by a consensus panel of experts and administered to 210 dental patients aged 4-11 years from three Italian Institutions. Internal reliability was assessed using the Cronbach's alpha correlation. A sub-sample of 60 children was selected for test-retest analysis. CFSS-DS and MCDAS, plus a VAS scale, rated both by children and parents, were validated using as gold standard the 4-item Frankl scale for behaviours assessed by dentists. RESULTS: Mean CFSS-DS score was 30.8 (SD: 11.1) and mean MCDAS score was 17.9 (SD: 7.2), significantly higher among children aged 4-7 years and among children at their first dental visit. The alpha value for internal reliability was 0.90 (95%, CI= 0.88-0.92) for CFSS-DS and 0.87 (95% CI=0.85-0.90) for MCDAS. Both CFSS-DS and MCDAS showed good test-retest reliability (rsp= 0.80; p<0.001 for both scales). CFSS-DS and MCDAS predicted a Frankl score ≤2 (i.e., indicating children with an uncooperative behaviour) with a fair accuracy (AUC=0.69 and AUC=0.68, respectively). The VAS scale was more effective in predicting a negative behaviour (AUC=0.78). The scales self-reported by children were only slightly more accurate than those reported by parents. CONCLUSION: The Italian versions of the CFSS-DS and MCDAS are valid and reliable tools for the assessment of dental fear in Italian children aged 4-11 years. A simple, one-item VAS, and dental fear and anxiety evaluation by parents may be valid and quick alternatives to multi-item indices to predict an uncooperative children behaviour.

Brain arteriovenous malformations and seizures: an Italian study.

OBJECTIVE: To evaluate seizures as first clinical manifestation of brain arteriovenous malformations (AVMs), in relation to angioarchitectural features of these vascular anomalies. METHODS: We performed a prospective observational study, collecting records of patients with AVMs consecutively admitted to the Neurological and Neurosurgery Units of Perugia University and to the Neurosurgery Unit of Terni Hospital, during a 10-year period (1 January 2002 to 1 June 2012). Two groups of patients, with or without seizures as AVM first presentation, were analysed to identify differences in demographic and angiographic features. A multivariate logistic regression model was also developed. RESULTS: We examined 101 patients with AVMs, 55 male and 46 female. Seizures were the initial clinical manifestation in 31 (30.7%) patients. We found a significant difference (p<0.05) between two groups of patients, with or without seizures as AVM first presentation concerning location, side, topography and venous drainage. A multivariate logistic regression model showed that clinical presentation with seizures was correlated with a location in the temporal and frontal lobes, and with a superficial topography. The strongest association (OR 3.48; 95% CI 1.77 to 6.85) was observed between seizures and AVM location in the temporal lobe. CONCLUSIONS: Vascular remodelling and haemodynamic changes of AVMs might create conditions for epileptogenesis. However, here we show that malformations with specific angiographic characteristics are more likely to be associated with seizures as first clinical presentation. Location is the most important feature related to epilepsy and in particular the temporal lobe might play a crucial role in the occurrence of seizure.

Lower urinary tract symptoms and urodynamic dysfunction in clinically isolated syndromes suggestive of multiple sclerosis.

BACKGROUND AND PURPOSE: Urinary symptoms associated with multiple sclerosis (MS) are common and negatively impact on quality of life, representing a considerable psychosocial and economic burden, often requiring care and hospitalization. Although the importance of identifying and adequately treating urinary symptoms in MS is now well recognized, there is no information, to date, about the real prevalence and impact of bladder symptoms in patients with clinically isolated syndromes (CISs) suggestive of MS. METHODS: The aim of the present study was to investigate, in a cohort of patients with a diagnosis of CIS suggestive of MS, the prevalence of urinary tract symptoms, their impact on quality of life measures and their association with functional urodynamic dysfunctions. Patients underwent a complete neurological and urological visit, urodynamic investigation and the MSQoL-54 questionnaire. RESULTS: Twenty-eight consecutive patients presenting with CISs were enrolled in the study; 53.6% of CIS patients reported urinary symptoms, 46.7% reporting irritative symptoms, 33.3% both irritative and obstructive symptoms and 20% obstructive symptoms alone. Urodynamic abnormalities were observed in 57.1% of the CIS patients. In 17.9% of the CIS patients urodynamic dysfunctions were asymptomatic. The presence of urinary symptoms was associated with lower scores on specific quality of life domains, particularly in women with obstructive symptoms. CONCLUSIONS: A high prevalence of urinary symptoms and urodynamic dysfunctions in patients with CISs and an association of urinary symptoms with quality of life measures were found. These results highlight the importance of identifying and optimally treating urinary symptoms also at the very early stages of MS.

A magnetization transfer study of mild and advanced Parkinson's disease.

BACKGROUND AND PURPOSE: Magnetization transfer ratio (MTR) technique has identified brain changes in grey and white matter in Parkinson's disease (PD), even in the early phase. However, how these tissue changes differ along the course of the illness is still unclear. This study was aimed at investigating how MTR values change from mild PD (PD1) to patients with advanced PD (PD2). METHODS: We measured MTR values by region of interest, in 11 PD1, 11 PD2 and 10 healthy age-matched subjects. RESULTS: Compared with controls, patients with PD1 exhibited a significant MTR reduction in substantia nigra pars compacta, substantia nigra pars reticulata, putamen, periventricular white matter and parietal white matter. In addition to the changes observed in PD1, the PD2 group exhibited a significant MTR reduction in caudate, pons, frontal white matter and lateral thalamus. CONCLUSION: These results suggest that MTR might reflect morphological changes induced by the disease in distinct brain areas at different stages.

HIV-Dementia Scale as a screening tool for the detection of subcortical cognitive deficits: validation of the Italian version.

Mini-Mental State Examination (MMSE) lacks of sensitivity in detecting cognitive deficits associated with subcortical damage. The HIV-Dementia Scale (HDS), a screening tool originally created for detecting cognitive impairment due to subcortical damage in HIV + patients, has proved to be useful in other neurological diseases. Until now, an Italian version of the HDS is not available. We aimed at: (1) validating the HDS Italian version (HDS-IT) in a cohort of cognitively healthy subjects (CN); (2) exploring the suitability of HDS-IT in detecting cognitive impairment due to subcortical damage (scCI). The psychometric properties of the HDS-IT were assessed in 180 CN (mean age 67.6 ± 8.3, range 41-84) with regard to item-total correlation, test-retest reliability and convergent validity with MMSE. Item-total correlations ranged 0.44-0.72. Test-retest reliability was 0.70 (p < 0.001). The HDS-IT scores were positively associated with MMSE score (rS = 0.49, p < 0.001). Then, both the HDS-IT and the MMSE were administered to 44 scCI subjects (mean age 64.9 ± 10.6, range 41-84). Mean HDS-IT total score was close to the original version and significantly lower in the scCI group compared to CN (8.6 ± 3.6 vs. 12.6 ± 2.5, p < 0.001). ROC analysis yielded an optimal cutoff value of 11, with sensitivity of 0.70 and specificity of 0.82. Patients showed poorer scores on HDS-IT compared to CN (12.6 ± 2.5 vs. 8.6 ± 3.6, p < 0.001). Our results support the use of HDS-IT as a screening tool suitable for detecting cognitive deficits with prevalent subcortical pattern, being complementary to MMSE in clinical practice.

Degradation of endocannabinoids in chronic migraine and medication overuse headache.

Chronic migraine (CM) is frequently associated with medication overuse headache (MOH). The endocannabinoid system plays a role in modulating pain including headache and is involved in the common neurobiological mechanism underlying drug addiction and reward system. Anandamide (AEA) and 2-arachidonoylglycerol are the most biologically active endocannabinoids, which bind to both central and peripheral cannabinoid receptors. The level of AEA in the extracellular space is controlled by cellular uptake via a specific AEA membrane transporter (AMT), followed by intracellular degradation by the enzyme AEA hydrolase (fatty acid amide hydrolase, FAAH). AMT and FAAH have also been characterized in human platelets. We assayed the activity of AMT and of FAAH in platelets isolated from four groups of subjects: MOH, CM without MOH, episodic migraine and controls. AMT and FAAH were significantly reduced in CM and MOH, compared to either controls or episodic migraine group. This latter finding was observed in both males and females with CM and MOH. Changes observed in the biochemical mechanisms degrading endogenous cannabinoids may reflect an adaptative behaviour induced by chronic headache and/or drug overuse.

A 1H magnetic resonance spectroscopy study in patients with obstructive sleep apnea.

BACKGROUND AND PURPOSE: Repeated episodes of hypoxia, hypercapnia and transient blood pressure elevation in obstructive sleep apnea syndrome (OSAS) may damage neutral structures and induce cerebral metabolic impairment. This study aimed to determine the impact of OSAS on cerebral metabolites measured by (1)H magnetic resonance spectroscopy ((1)H -MRS). METHODS: Twenty OSAS patients underwent standard overnight polysomnography and (1)H-MRS separately. Proton volumes of interest (VOIs) were placed in frontal and midtemporal regions bilaterally. RESULTS: Significantly lower values of the N-acetylaspartate (NAA)/creatine (Cr) ratio were found in frontal regions (P < 0.004) compared with 20 age-matched control subjects. A significant increase in the myo-inositol (Ins)/Cr ratio was evident bilaterally in temporal and frontal regions (P < 0.00002 and P < 0.04). Choline (Cho)/Cr ratio values were also significantly greater in temporal regions (P < 0.00001). A significant negative correlation (r = -0.51, P < 0.03) was found between the apnea-hypopnea index (AHI) and NAA/Cr ratio in the frontal regions of OSAS patients. CONCLUSIONS: Reduction in the NAA/Cr ratio in frontal regions of OSAS patients could be related to neural loss. Increase in the Cho/Cr ratio in temporal regions and Ins/Cr ratio in both frontal and temporal regions could be interpreted as evidence of membrane breakdown and reactive gliosis, respectively, consequent to repeated episodes of hypoxia in OSAS.